28
Service Manual
VMH 30, 36 SerieS
Heat Controller
26
The unit runs with T3
＜
37.5°F(3°C) for 40 minutes and T3 stays lower than 2
1
°F(-6°C) for more than 3
minutes.
The unit runs with T3
＜
37.5°F(3°C) for 80 minutes and T3 stays lower than 25°F(-4°C) for more than
3 minutes.
Condition 2: If T4>3
2
°F(0°C),
The program judges according to condition 1, if the two items are satisfied, then it judges if T2 has
decreased more than
9
°F(5°C). When T2 has decreased more than
9
°F(5°C), it enter the defrosting
mode.
Condition 3:
No matter what value T4 is, if the machine runs with T3
＜
37.5°F(3°C) for more than 120
minutes and T3 keeps lower than 25°F(-4°C) for more than 3 minutes, the machine will defrost, no
matter if T2 drops for more than
9
°F(5°C) or not.
Condition of ending defrosting:
If any one of following items is satisfied, defrosting will finish and the machine will turn to normal
heating mode.
T3 rises to be higher than
59°F(15°C).
T3 rises to be higher than
46
°F(
8
°C) and remains for 80 seconds.
The machine has run for 10 minutes in defrosting.
The defrosting action
：
10 seconds
30 seconds
70 seconds
60 seconds
